大鼠脑梗死后乏氧组织变化与血管增生的关系

目的： 探索脑梗死后乏氧组织的变化与血管增生的关系。方法：利用大鼠脑缺血1.5 h再灌注（1.5 h IR组）和持续缺血（PI组）的线栓模型，采用2-(2-硝基-1氢-硝基咪唑-1-羟基)-氮-（2，2，3，3，3-5氟嘌呤）乙酰唑胺（EF5）和血管性假性血友病因子 (vWF)免疫荧光方法观察乏氧组织和微血管密度（MVD），比较2组术后3 d、7 d、14 d缺血侧大脑半球皮层的MVD以及与乏氧组织的关系。结果： 1.5 h IR组术后3 d、7 d、14 d均见乏氧组织存在，PI组乏氧组织仅存在3 d，假手术组不存在乏氧组织。各观察时点的乏氧组织内部MVD均较周围区域的MVD小（均P<0.01）。随着时间的延长，1.5 h IR组和PI组的皮层MVD均不断增大（均P<0.01），而1.5 h IR组7 d和14 d的皮层MVD均高于PI组（均P<0.01）。结论： 脑梗死后乏氧组织出现在微血管稀疏的区域。微血管增生程度的差异是导致乏氧组织持续时间不同的原因之一。

Relationship between change of hypoxic tissue and vascular proliferation after cerebral infarction in rats

AIM: To clarify the relationship between the change of hypoxic tissue and vascular proliferation after cerebral infarction. METHODS: Rats with middle cerebral artery occlusion were randomly divided into 1.5 h ischemia-reperfusion (1.5 h IR) group and permanent ischemia (PI) group. Double staining by immunofluorescence was used to identify the hypoxic tissue and microvessels by EF5 and vWF labelings, respectively. On 3 d, 7 d and 14 d post-operation, microvessel density (MVD) and hypoxic tissue in ischemic cortex were observed. RESULTS: Hypoxic tissues existed from 3 d to 14 d post-operation in 1.5 h IR group and disappeared after 3 d in PI group. The MVD within hypoxic tissue was smaller than that around it at all observed time points (all P<0.01). With the lapse of time, MVD in ischemic cortex gradually increased both in 1.5 IR and PI groups (all P<0.01) and was bigger in 1.5 h IR group than that in PI group on 7 d and 14 d (both P<0.01). CONCLUSION: Hypoxic tissues mainly locate in areas of sparse microvessel after cerebral infarction and their duration is partially dependent on the grade of microvessel proliferation in ischemic cortex.